Pump liner



June 18, 1940. p L SCOTT y 2,204,626

PUMY` LINER Filed Nov. 12, 1936 @w www@ M//Y/ f m n N (nl 4vum'raoSTATES PATENT OFFICE rumana@ secu. calmo, nl., saigner u su DielelTractor Corporation, La Porte, 1nd.. acorporation o! New YorkApplication November iz, 193e, semina. 110.4114 s calm. (ci. :cs-4) Thisinvention relates tothe construction/and the method of constructing a`barrel in which a member is Vto reciprocate and in which tight nts areessential. e l

l l The invention may be embodied in many constructions: One for whichit is particularly well suited comprises a pump. When embodied in a pumpthe invention includes thepump barrel which is formed of a liner and ajacket or outer 0 member. 'I'he liner is perforated to receive a pistonwhich may reciprocate within it. The

i invention is not limited in its application to a pump and whereapplied to a pump it is not limited to any particular forni orAconstruction i5 of pump. Therefore, inthe present drawing,

which illustrates two forms of a pump barrel construction, only so muchof the pump is shown as to indicate the general arrangement of theparts.

An object of `the invention is to provide means i whereby the pump lineris put under initial compressior, that is to say, vwhereby it iscompressed initially before use.V Another object of the invention is toprovide a pump barrel in which the tendency to distortion of the lineris overcome and in which any growth of the metal of the liner whichoccurs will be largely inwardly, tending thus to close the bore against.the. piston or plungerso that during the lift of the pump the bore doesnot growlarger and leakage is thus B0 avoided.

Another object is to provide a method of. manufacturing 4 a pump orother barrel having the properties described.

j Other objects will appear from time to time 85 in the specication andclaims.

The invention is illustrated more or less diagrammatically in theaccompanying drawing, whereinl Figure 1 is a longitudinal sectionthrough a 40 portion of a pump and pump barrel, illustrating one form ofthe barrel construction; and

Figure 2 is a similar sectional detail illustrating a modiiied form ofbarrel construction.

Like parts are designated by like characters 45 throughout thespecification and drawing.

l is a portion of a pump housing which is prov vided with a cavity 2.'I'he housing may have ears or other lateral projections 3, perforatedas at to receive fastening means by which the 60 pump `may be secured toany desired base. Adjacent its upper end the pump housing i is providedwith an inwardly extending part which partially closes the cavity 2 atthat end. The portion B-may be shouldered as at 6. 55 Ihe barrelconstruction includes in general a plunger enclosing and guidingassembly including two parts, the first being a jacket or surroundingmember 1 which is preferably provided with an inner tapered bore l andmay have a laterally extending shoulder or iiange 9 of such I size as tobe seated in the perforation or opening in the housing portion!` andbeing -seated also against the shoulder t. The jacket or surroundingportion may be of any suitable material but is preferably of onestrongly resistant to .deforl0 mation, that is to s'ay, more resistantto deformation thanv the liner. Frequently in practice the jacket membermay be of steel.

In the form of the inventionl illustrated in Figure 1 a liner i0 isprovided. This liner ll has a cylindrical bore Il and its exterior istapered as at i2, the taper corresponding to the taper I of thejacket 1. IWhile'the liner need not be ofthe same length as the jacket 1it frequently is. The linery may also be ilared adjacent one end as atI3 to receive a sealing or joint-making member in a mannerv which4 willshortly be described.

In the form illustrated in Figure 1, i4 is a second housing portion'co-operating with` the 26- housing portion i in the formation of a com-Aplete pump housing. A sealing member I5 is positioned partly in theflared portion I3 of the liner I! and partly in a ared portion ii made.at one end of the cavity or bore i1 within the 80 housing section I4.The details of the pump housing need not further be described and nodescription of the passages to and from the pump is necessary becausethe barrel of the present lnvention may be applied to almost any type ofpump, or in fact to almost any construction in which a memberreciprocates within a barrel.

In the form shown in Figure 1 a piston i8 is provided which iits tightlywithin the bore Il of the liner I0. This piston or plunger may be oi' 0any desired shape but in thel form shown has a.

generally conical point i9. The plunger may be reciprocated by anydesired means. vAs shown. however, the end of the plunger opposite thetapered end is rounded and adjacent this end there is formed an annulargroove 20 into which is received a spring-retaining plate 2i. Asprlng 22surrounds the barrel, bears at one end against the portion .t of thepump housing section i and L bears at the other end against the plate2l. A 6o cross head 22a is mounted within the cavity 2 ofthe housingsection i for reciprocation. It surrounds the plunger, barrel and springassembly above described., 4It may carry a contact member 23 which fitswithin a perforation 24 in 55 in Figure 1 is ilanged as at 2 5to.it-`again`st a corresponding shoulder formed in the bottom oi thevcross hea'd-.-Aspring 26 is sprung into a corresponding groove in theexposed end of the' member 23 to hold` it in place.

head of the plunger Il contacts the opposing sur:

face of'themember y23'. It will beunderstood that the cross head may bereciprocated by any mechanism. Itv moves upward in the form` shown inFigure i to compress the spring 22 .and yto force the plunger inwardly.When the spring is free for reverse movement vit forces the cross headand plunger downwardly. i f v Y.

In manufacture the materials chosen 'iriaaf'be for the liner arelatively soft material such as cast iron and for the jacket or sleeve.surrounds ingit a relatively harder material suchas steel. However, aliner. and sleeve assemb1y"can"be made satisfactorily .where bothmaterialsare lof the same hardness. Thejclosing up which occurs when thesleeve is compressed on theiliner either by being drivenon in thetapered form or by being shrunk or pressed or otherwise tightened aboutthe liner, may occur where both materials are oi the same hardness orhave the same modulusof elasticity. InnormalV practice it ispreferableto make the liner of a material having a greater modulus ofelasticity thanv that of the sleeve but where it is desired the' sleeveand liner may have similar or identicalfmoduli of elasticity. y f

Cast iron has been spoken of as a suitable liner. Experience in the artof pumps has shown it to be a suitable material for many reasons.Experience has also shown that cast iron changes both its shape and sizein the course of time.

This eiect is sometimes called growth or vwarpage and forms a seriousobjection tothe use oi' the material `as a liner for the barrel of apump crother analogous device, and`it is particularly objectionablewhere cast iron is to be used as a pump barrel for fuel pumps whererelatively high pressures prevail. In those vforms Iof the presentdevice in which cast ironia used it is selected for its manyadvantageous qualities. among which are goodbearing qualities, goodwearingqualities andgood machining qualities.

The liner, whether it be of cast iron or of other suitable material ismade to approximately suitable shape and is then inserted in a sleeve orJacket of a material of high tensile strength. The

two partsmay beassembled by .means of the taper iit shown in the form ofFigure l, the liner being forced into the tapered jacket or sleeve.producing a press iit and the liner is actually driven into the taperfarther than it would readilygo. This press t produces a tension in thesleeve or jacket 1 and a corresponding compression in the liner i0 andpreferably this compression will be made greater than the hydrostatic orother load which may be` applied in use internally to the liner.

Inthe form of the'device shown in Figure 2, a retaining sleeve or jacket21 isl used. 'Its outer shape and contour are essentially the same as.that of the sleeve 1. Internally it is not tapered,

however, and it is. provided with a cylindrical bore. l The liner 28,which fits within it, also is not tapered on its exterior.l Interiorlyit has a bore 29 which is preferably flared outwardly as at lll for thereason above `described in ccnnecf.

tion. with the flare Il in the liner lil. In' the manufacture ofthe formof the device shown The. roundedand required excessive amounts of time.

is because no way has previously been known 2.204,0@ y l its bottom.This member in the form shown in lligure'ittiielier; which maybe of castiron or other suitable material, is iltted and positioned within thesleeve 21 which may be of, steel or other material of 'high tensilestrength with a shrink fit or a press fit or otherwise, so that tenlsionis produced in the sleeve `and-compression in theylinen'llhe'restuts'i'f'- this form of con'- struction' are generallythe same, therefor-aas those of the form of Figure 1 and the eiIect ofeach is to produce a compression ofthe liner before use and to vproducea construction in which growthf or other change in the shape or size ofthe liner cannot occur to as great an" extentoutwardly and cannotresult, therefore.

in an enlargement of the bore, and any such 'growth which may occur willbe largely inward away from the plunger and thus to produce leakage. I

Heretoiore an accurate mating between a plunger and barrel in apackingless pump, that is too say, in which the main sealing eiiect isobtained .by the.' nicety of fit between a plunger and barrel ofrelatively hard materials rather than by soft and easily compressiblematerials, has proved a very, serious problem. General practice hasinvolved hand lapping operations to extreme accuracies which has provedboth costly This to handle these hard materials except by some form ofcutting or abrasion. My invention overcomes this diillculty in that eventhough the materials are hard they do have slight elasticity and I amtaking advantage of this slight elas-` ticity to change the size aminute amount which, however, is suflicient to produce the desired fit.

l. In combination in a pump having a barrel and a piston, a multi-partbarrel having a cy- Alindrical bore, adapted to receive a piston, one ofsaid parts comprising a unitary, ferrous liner, a second part situatedoutside of said liner and acting thereupon, said second part being fixed.with relation to said liner during pump operation and exerting apredetermined degree vof initial compression upon said liner saidcompression reducing the diameter of the bore of said liner -in minuteamount and causing it tio fit and mate with the plunger to microscopicaccuracy and producing stresses within the mav terial of said linerwhich stresses are well within the elastic limit of the material used;

2. In combination in a pump having a barrel and a piston, a multi-partbarrel having a cylin-` drical bore, adapted to receive a piston, one ofsaid parts comprising a unitary liner formed oi.' hard metal, a secondpart situated outside of said liner and\acting thereupon, said secondpart being ilxed with relation to said liner during pump operation andexerting initial compression'upon said liner and producing stresseswithin the material of said liner, said compression causingl 1 withinthe material of said liner stress greater than that produced therein byinternal 'loading during normal operatonof the pump.

3. In combination in a pump having a barrel and a piston, a multi-partbarrel having a cylindrical bore, adapted to receive a piston, one ofsaid parts comprising a unitary liner, and being formed of a relativelyhard material having a tendency to grow, a second part situated out-nannessa side of said liner and acting thereupon.. said second part beingxed with relation to said liner during pump operation and exertinginitial coml pression upon said liner and producing stress actingthereupon to compel said "growth to occur largely inwardly, said secondpart exerting initial compression upon said liner and producing stresswithin the material oiIv said liner.

5. In combination in a pump having a barrel and a piston, a multipart`barrel having a cylindrical bore, adapted to receive a piston, one ofsaid parts comprising a unitary liner formed of relatively hard metaland being exteriorly tapered, a second part correspondingly interiorlytapered situated outside of said liner and acting thereupon., saidsecond part being fixed with relation to said liner during pumpoperation and exertingy initial compression upon said liner andproducing stress within the material of Vsaid liner. 4

6. In combina-tion in a pump having a barrel and a piston, a multi-partbarrel having a cylindrical bore, adapted to receive a piston, one ofsaid parts comprising a unitary liner formed of relatively hard metaland beingexteriorly tapered, a second part correspondingly interiorlytapered situated outside of and in contact with said liner and actingthereupon. said second part being iixed with relation to said linerduring pump operation and exerting compression initially upon said linerand producing stress within the material of said liner.

7. In combination in a pump having a barrel anda piston, a multi-'partbarrel' having a cylin-J drical bore, adapted to receive a piston. oneot said parts comprising a liner of one modulus oi elasticity, a secondpart situated outside of said liner and acting thereupon, said second.part being fixed with relation to said liner during pump operation andhaving a lower modulus of elasticity than said liner and exertingcompression upon `said liner and producing stress within the material ofsaid liner.

8. In combination in. a pump having a and a piston, a multi-part barrel.one of said parts comprising a liner, a second part situated outside otsaid liner and acting thereupon. said second part exerting compressionupon saidliner and producing strass within the'materiai of said liner,said liner being of a material having a greater modulus ot elasticitythan that of the outer member of the barrel.

9. In combination in a pump having a barrel and a piston. a multi-partbarrel. one of said parts comprising unitary a liner formed ofrelatively hard iron, a second part formed of relatively harder steelsituated outside of said liner and acting thereupon, said second partexerting A compression initially upon said liner; and prducing stresswithinl the material of said liner.

